Both bivalent and quadrivalent cervical cancer vaccines can be given at age 40. Although older, both of these vaccines are effective, and cervical cancer vaccines usually cannot be given over age 45. HPV monitoring is generally not required before the cervical cancer vaccine is administered, because such vaccination is mainly to prevent future re-infection with HPV virus, and has no effect on viruses that have already been infected, or the original HPV virus infection. After HPV vaccination, it is also necessary to do regular pre-cervical cancer screening. Because there are still some HPV viruses that are not completely covered by this vaccine, there is still a possibility of cervical cancer.